Electric vehicles are generally provided with a charger for the total recharging of their batteries all together comprising a connector for distribution of electrical energy. This charger therefore preferably is adaptable to all types of available voltage sources.
However, each time that the vehicle slows down, its motor becomes a voltage generator and recharges the batteries with a part of the energy preceedingly accumulated by the vechicle in the form of kinetic energy. For reasons of convenience of driving and safety, there is initially a low recovery of energy when the operator releases the accelerator, which permits obtaining a motor brakage substantially identical to that obtained with internal combustion engines, this recovery of energy progressively increasing as the operator more vigorously activates the brake pedal.
When the speed of the vehicle is low, the electromotive force of the motor can be less than that of the batteries. It is therefore not possible to recover the kinetic energy of the vehicle. To avoid discharge of the batteries, the motor can be short circuited, in which case, at low speed, the kinetic energy of the vehicle for the charging of the batteries is lost.
To resolve this problem which is posed at low speeds, it has been proposed to mount on the motor shaft a small auxiliary generator delivering, for such speed, an electromotive voltage of much greater value than that furnished by the main drive machine. Since this auxiliary generator only operates in a relatively short time, it can provide a high extra charge and thus deliver substantial current for its size. However, the possibilities for this arrangement are limited because the main machine which assures the drive of the vehicle is generally a machine having series excitation which is relatively impractical to control. These machines are thus utilized separately and the inertia of the assembly is substantial.